Verbal Reasoning - Arithmetic Reasoning - Discussion
Discussion Forum : Arithmetic Reasoning - Section 1 (Q.No. 26)
26.
Five bells begin to toll together and toll respectively at intervals of 6, 5, 7, 10 and 12 seconds. How many times will they toll together in one hour excluding the one at the start ?
Answer: Option
Explanation:
L.C.M. of 6, 5, 7, 10 and 12 is 420.
So, the bells will toll together after every 420 seconds i.e. 7 minutes.
Now, 7 x 8 = 56 and 7 x 9 = 63.
Thus, in 1-hour (or 60 minutes), the bells will toll together 8 times, excluding the one at the start.
Discussion:
17 comments Page 2 of 2.
Nidhi said:
8 years ago
Ans is 9.
Lcm is 336.
Now 336 ÷ 60 is 5.6.
5.6 * 10 = 56.
Excluding first term, we get 9.
Lcm is 336.
Now 336 ÷ 60 is 5.6.
5.6 * 10 = 56.
Excluding first term, we get 9.
Priya said:
1 decade ago
How did we exclude the bell tolled at the first time while getting the answer as 8 times?
Ved Prakash said:
1 decade ago
I also want to know why 7*8 and 7*9 are multiplied ?
Revanth said:
8 years ago
Thank you for the explanation @Jaspreet Singh.
Purva said:
1 decade ago
Why multiply by 7*8 and so on? Please tel me.
Siyad said:
8 years ago
Thanks for explaining @Jaspreet Singh.
Sourav patra said:
5 years ago
Agree @Sushil Ojha.
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